Fair Value Measurements (Narrative) (Detail) - USD ($) |
3 Months Ended | |
|---|---|---|
Mar. 31, 2016 |
Mar. 31, 2015 |
|
| Fair Value Disclosures [Abstract] | ||
| Fair value assets, Level 1 to Level 2 transfers amount | $ 0 | $ 0 |
| Fair value assets, Level 2 to Level 1 transfers amount | 0 | 0 |
| Transfers into Level 3 | 2,412,000 | 0 |
| Transfers out of Level 3 | $ 35,799,000 | $ 0 |